Condition Guide

Eczema — Atopic Dermatitis Explained

IgE testing in eczema, blood tests for allergy and infection, trigger identification, and the stepwise eczema treatment ladder.

What is Eczema?

Eczema (atopic dermatitis) is a chronic inflammatory skin condition characterised by intensely itchy, dry, inflamed skin that typically follows a relapsing-remitting course. It affects approximately 20% of children and 3% of adults worldwide. Eczema is part of the "atopic triad" — many patients also have asthma and allergic rhinitis. The condition results from a combination of genetic skin barrier defects and immune dysregulation.

Types of Eczema

TypeFeaturesCommon Sites
Atopic DermatitisMost common; linked to allergy, family history, asthmaFlexures (elbow, knee creases), face in children
Contact DermatitisTriggered by specific allergen (nickel, latex, cosmetics) or irritant (soap, detergent)Wherever contact occurs
Seborrhoeic DermatitisYeast-related; scalp, face, chest — not truly "atopic"Scalp (dandruff), T-zone, chest
Discoid (Nummular) EczemaCoin-shaped patches; often in adults; can be very itchyLimbs, trunk

Blood Tests in Eczema

TestFinding in EczemaPurpose
Total IgEElevated in ~80% of atopic eczema patientsConfirms atopic status; very high levels suggest significant allergic sensitisation
Specific IgE (RAST / ImmunoCAP)Identifies specific allergens causing sensitisationTests for house dust mite, pet dander, food allergens (milk, egg, peanut in children)
CBC — EosinophilsElevated eosinophils (eosinophilia) common in atopic conditionsMarker of atopic and parasitic activity
Skin swab for cultureStaphylococcus aureus colonises eczema skin in majority of patientsIdentifies secondary bacterial infection requiring antibiotic treatment

Common Triggers

Trigger CategoryExamplesHow to Manage
Environmental allergensHouse dust mites, pollen, pet dander, mouldDust mite covers, regular vacuuming, HEPA filters
Food triggers (mainly children)Eggs, cow's milk, peanuts, wheat, soyIdentify through dietary diary and supervised elimination; avoid confirmed triggers
Psychological stressExams, life stressorsStress management, mindfulness; flares predictably follow stressful periods
Heat and sweatingExercise, hot weatherCool showers after exercise, lightweight breathable clothing
Soaps, detergents, fragrancesBubble baths, scented productsUse fragrance-free, soap-free cleansers and emollients

Treatment Ladder

Step 1: Moisturisers (Emollients) — Used Continuously

The cornerstone of eczema management. Apply generously multiple times daily to ALL skin, not just affected areas. Use immediately after bathing (pat dry, don't rub). Examples: liquid paraffin-based creams, Cetaphil, Dove, or prescribed emollients. Using 250–500g per week is not unusual for significant eczema.

Step 2: Topical Corticosteroids for Flares

Apply to active eczema patches only during flares. Use the lowest potency that controls the flare. Mild steroid (hydrocortisone 1%) for face; moderate (betamethasone valerate 0.025%) for body; potent (betamethasone dipropionate 0.05%) for thick lichenified skin. Use for short bursts (7–14 days), then stop. Fingertip unit dosing guides correct application.

Step 3: Topical Calcineurin Inhibitors

Tacrolimus (Protopic) and pimecrolimus (Elidel) are steroid-free anti-inflammatory creams. Particularly useful on the face and eyelids where steroids cause side effects. Good for long-term maintenance on sensitive areas.

Step 4: Dupilumab (Biologic) for Severe Eczema

Dupilumab (Dupixent) is a biologic injection targeting IL-4 and IL-13 — the key inflammatory cytokines in eczema. It is highly effective for moderate-to-severe atopic dermatitis not controlled by topical treatments. Given as subcutaneous injection every 2 weeks. Approved for adults and children ≥6 years.

Important: Do not stop topical steroids abruptly after prolonged use on large areas — taper gradually. Topical steroid phobia is common but the correct use of appropriate strength steroids is safe and effective for short periods.

Questions to Ask Your Doctor

Medical Disclaimer: This information is for educational purposes only and does not constitute medical advice. Eczema management should be tailored by a dermatologist or allergy specialist.